1. Field of the Disclosure
The present disclosure relates generally to monitoring and control of metering systems. More particularly, the present disclosure relates to systems and methods for simultaneous communications on Modbus and DNP 3.0 over Ethernet for an electronic power meter.
2. Description of the Related Art
The metering architecture that exists in the power utility field today is geared toward providing enough information to accurately monitor and control a variety of metering devices installed at numerous substations. To achieve these objectives, it is essential that communication between a central utility station and substations be time- and cost-efficient, quick updating, as well as reliable.
Historically, meters measuring electrical energy have used measurement devices, which mechanically monitor the subscriber's usage and display a reading of the usage at the meter itself. Consequently, the reading of these meters has required that human meter readers physically go to the site of the meter and manually document the readings. Clearly, this approach relies very heavily on human intervention and, thus, is very costly, time-consuming, and prone to human error. As the number of meters in a typical utility's service region has increased, in some cases into the millions, human meter reading has become prohibitive in terms of time and money.
Over time, these conventional meters were made using microprocessor technologies, which enabled them to be read using a serial protocol and interface. This enabled the meters to be used in series to obtain readings back at a remote terminal unit (RTU) for remote SCADA (Supervisory Control and Data Acquisition) interrogation. For example, FIG. 1 is a schematic view of a conventional system for monitoring and controlling a plurality of substations. That is, referring to FIG. 1, meters 1, 2, and 3 can communicate serially through each other. However, in order for a SCADA master 5 to receive information from meter 3, the information must be passed from meter 3 to meter 2, from meter 2 to meter 1, from meter 1 to an RTU 4, and from the RTU 4 to the SCADA master 5.
Realization of such communication may be accomplished by a standard open protocol known as DNP 3.0. This protocol is configured to provide the power utility with a serial language to speak to the substations and to allow the utility to use outage detection software, generically labeled in the industry as SCADA. In other words, communication between each of the meters and, for example, a central station is realized through a respective serial port and is thus limited to a respective pair coupled to one another via a dedicated channel. DNP 3.0 is optimized for a round-robin type disturbance awareness response.
Furthermore, utility companies communicate to metering and data telemetry devices in substations using different serial based protocols. Different departments within a given utility company have standardized on different protocols which are optimized for the applications they have. For instance, while SCADA systems operate at peak performance using the DNP 3.0 protocol, this protocol is inefficient and difficult to manage when applied to metering departments, system planning, and estimation and power plant DCS systems. As products became more sophisticated, these differing departments wanted to obtain data from one instrument that gave them all the needed disturbance and recorded data. To date, these various departments have had to install separate equipment in substations, separate serial channels, and a variety of protocols to access the data of the monitoring instrument. This is often a costly endeavor, thus a need exists for a system for simultaneously communicating in a plurality of protocols between a monitoring instrument and the various departments in a central utility station. Furthermore, there has been a desire in the industry to eliminate serial protocols and channels and have the various data transmitted over LANs (local area networks) using dedicated T1 or frame relay networks.